Sub Class C Reverse Domain Name System Zone Compilation

1. A subnetted class C internet protocol (IP) address domain name system (DNS) reverse zone file compiling server, comprising: a memory; a processor; and an application stored in the memory that, when executed by the processor parses a plurality of subnetted class C IP address DNS reverse zone files, each subnetted class C IP address DNS reverse zone file defining a mapping from at least one DNS canonical name (CNAME) to a domain name of a subnetted class C internet protocol address zone, generates a class C IP address DNS reverse zone file associated with a starting class C internet protocol address based on the parsing of the plurality of subnetted class C IP address DNS reverse zone files, wherein the class C IP address DNS reverse zone file comprises an entry for each of assigned internet protocol addresses, wherein each entry for each of the assigned internet protocol addresses directly maps a domain name to an internet protocol address and does not indicate a DNS canonical name type, and transmits the class C IP address DNS reverse zone file associated with a class C internet protocol address block to an authoritative DNS server, whereby reverse DNS look-up of domain names associated with subnetted class C internet protocol addresses using the DNS service is promoted.

2. The server of claim 1 , wherein the authoritative DNS server is a primary DNS server, and the class C IP address DNS reverse zone file is copied from the primary DNS server to a secondary DNS server when the primary DNS server receives a new or updated class C IP address DNS reverse zone file.

3. The server of claim 1 , wherein the authoritative DNS server is a DNS name server that replies to DNS queries with answers that have been configured by an original source.

4. The server of claim 1 , wherein the class C IP address DNS reverse zone file is compiled based on all the subnetted class C IP address DNS reverse zone files within the same class C internet protocol address block.

5. The server of claim 1 , wherein only one zone is generated by combining all subnetted class C internet protocol address zones of the subnetted class C IP address DNS reverse zone files within the same class C internet protocol address block, and the one zone is configured in the settings of the compiling server.

6. The server of claim 1 , wherein a subnetted class C IP address DNS reverse zone file is updated when a subnetted class C internet protocol address zone is updated, and wherein a new class C IP address DNS reverse zone file is compiled when a subnetted class C IP address DNS reverse zone file is updated.

7. The server of claim 6 , wherein the previous class C IP address DNS reverse zone file is replaced by the newly generated class C IP address DNS reverse zone file.

8. The server of claim 1 , wherein the class C IP address DNS reverse zone file is compiled at a predefined time interval.

9. A subnetted class C internet protocol (IP) address domain name system (DNS) reverse zone file compiling server, comprising: a memory; a processor; and an application stored in the memory that, when executed by the processor parses a plurality of subnetted class C IP address DNS reverse zone files, each subnetted class C IP address DNS reverse zone file defining a mapping from at least one DNS canonical name (CNAME) to a domain name of a subnetted class C internet protocol address zone, generates a class B internet protocol address DNS reverse zone file associated with a starting class B internet protocol address based on the parsing of the plurality of subnetted class C IP address DNS reverse zone files, wherein the class B internet protocol address DNS reverse zone file comprises an entry for each of assigned internet protocol addresses, wherein each entry for each of the assigned internet protocol addresses directly maps a domain name to an internet protocol address and does not indicate a DNS canonical name type, and transmits the class B internet protocol address DNS reverse zone file associated with a class B internet protocol address block to an authoritative DNS server, whereby reverse DNS look-up of domain names associated with subnetted class C internet protocol addresses using the DNS service is promoted.

10. The server of claim 9 , wherein a subnetted class C internet protocol address domain name system reverse lookup query is answered with only one response by the authoritative DNS server referencing to the compiled class B internet protocol address DNS reverse zone file.

11. The server of claim 9 , wherein only one zone of the class B internet protocol address block is created from combining all the subnetted class C internet protocol address zones within the same class B internet protocol address block defined in the subnetted class C IP address DNS reverse zone files.

12. The server of claim 9 , wherein when a change is made to a subnetted class C IP address DNS reverse zone file, the application compiles the class B internet protocol address DNS reverse zone file based on the most current subnetted class C IP address DNS reverse zone files, and transmits the newly compiled class B internet protocol address DNS reverse zone file to the authoritative DNS name server to replace the existing class B internet protocol address DNS reverse zone file.

13. The server of claim 9 , wherein an initial class C IP address DNS reverse zone file is used with the subnetted class C IP address DNS reverse zone files to compile the class B internet protocol address DNS reverse zone file.

14. The server of claim 9 , wherein the authoritative DNS server is a primary DNS server, and the class B internet protocol address DNS reverse zone file is copied from the primary DNS server to a secondary DNS server when the primary DNS server receives a new or updated class B internet protocol address DNS reverse zone file.

15. The server of claim 14 , wherein the secondary DNS server checks periodically on the primary DNS server for any change in the class B internet protocol address DNS reverse zone file.

16. The server of claim 14 , wherein the primary DNS server sends a notice to the secondary DNS server when a change is made to the class B internet protocol address DNS reverse zone file.

17. A method of compiling subnetted class C internet protocol (IP) address domain name system (DNS) reverse zone files, comprising: parsing an initial class C IP address DNS reverse zone file defining a mapping from at least one assigned internet protocol address to a DNS canonical name (CNAME) of a subnetted class C internet protocol address zone; parsing a plurality of subnetted class C IP address DNS reverse zone files, each subnetted class C IP address DNS reverse zone file defining a mapping from at least one DNS canonical name to a domain name of a subnetted class C internet protocol address zone; generating a class C IP address DNS reverse zone file associated with the starting class C internet protocol address based on the parsing of the plurality of subnetted class C IP address DNS reverse zone files, wherein the class C IP address DNS reverse zone file comprises an entry for each of assigned internet protocol addresses, wherein each entry for each of the assigned internet protocol addresses directly maps a domain name to an internet protocol address and does not indicate a DNS canonical name type; and transmitting the class C IP address DNS reverse zone file associated with the class C internet protocol address to an authoritative DNS server.

18. The method of claim 17 , wherein the authoritative DNS server handles subnetted class C internet protocol (IP) address domain name system (DNS) reverse lookup queries.

19. The method of claim 17 , wherein the class C IP address DNS reverse zone file is maintained by a compiling server of a network service provider.

20. The method of claim 17 , wherein Class C internet protocol addresses are internet protocol addresses whose leftmost three bits are fixed as 110 in the binary form.